Just had my MMMv3 Catch Fire... - RC-Monster Forums

eovnu87435ds · 11:05 PM

So I was running my converted hyper 7 PBS today when every Brushless R/C driver's nightmare came true for me... my Mamba Monster died

My setup was as follows.
10/46 gearing
MMMv3 (already replaced once)
Spektrum Sr3100 Rx
Spektrum DX3.0
Castle Neu 2650kv Monster combo motor
Airtronics servo
2 RC-Monster 2s2p 28/50c 5200mAh lipos in series (4s total)

MMM settings were all lightest for bashing purposes, and my cutoff was manual at 12.3v

In the beginning of the day, I was running it around the yard, tearing up the lawn, etc... and it ran fine for a half hour until i had to go... I came back later the same day, and continued to run the same setup, batteries were about half dead when i started.

Things were fine for about 5 minutes, when it stopped responding. It seemed to go to safety signal, as if it lost connection with the Tx. I restarted the Tx, and it reconnected and ran again. I did a run down the street at about 3/4 throttle, when it stopped again. Thats when I noticed my body glowing, and smoke billowing out of it. And I mean billowing- you couldn't see past the cloud of smoke it was so thick.

By the time i reach my hyper(~200 ft away)the smoke and fire had stopped. I ripped the body off and saw nothing but horror. I went to disconnect the batteries, and thats when I saw that my RC-M lipos were puffed.

Upon further inspection, one of the 6.5mm bullets was de-soldered from the MMM, as well as the negative battery input wire. they were both extremely hot.

After looking at the carnage and discussing it with ben(brushlessboy16) I think I have an idea of what happened... It seemed that the MMM overheated to the point where the one bullet became desoldered. Since there were only 2 phases operating the rotor would bounce between the 2 phases. Since the rotor wasn't spinning, the MMM was pulling more and more current to try and make the rotor spin, causing it to overheat eve more and catch fire and smoke. The extra amperage being pulled was then too much for the batteries. It would've finally stopped when enough current was being pulled from the batteries that the negative wire desoldered from the MMM as well.

Some other bits of info that might help in diagnosing this problem is that the drivetrain was completely free, so there was nothing mechanically holding anything back (if there even is anything that could), and the negative bullet was melted into the female bullet of the battery. What I still dont understand is why it would intermittently stop, and then work when i restarted my Tx, and what originally caused the MMM to heat up to the point where the bullet was desoldered...

Any help or support would be greatly appreciated

fastbaja5b · 02:24 AM

This is indeed disturbing, IMO with these failures and a number of Failures on the Savage Flux on 6s, I think Castle Creations needs to halt all development on new products and take a look at making these ESC's a bit more reliable.

Castle has (had) a reputation built on top customer service, lets hope these mega $$ deals with HPI and Traxxas now hasn't taken their eye off us "small consumers"

Speedys catching fire should not happen, and I am yet to see a "cheap chinese" Hobbywing 80 or 150A speedy fail as readily as this "high end" unit and that's a concern!

03.16.2009, 01:42 AM

wow thats buggered; My MMM V3 is already with CC for replacement after it died suddenly. At least mine was a quiet death
Hah

hootie7159 · 03.16.2009, 02:19 AM

How many flux esc's have failed ??? And I've only heard of about 4-5 MMMV3s failing (just on here).... And recognizing the amount of MMMV3s already being sold (due to on sale/sold out listings both online/eBay/LHS I still think the MMMv3s still have a pretty high sucess rate....EVERYOnE will post their MMMV3 problems and that's understandable....however , how many people actually post their success with the MMMv3s.....sucks that your MMMV3 has smoked though....BTW my MMMv1 finally died a silent death yesterday after almost 10 months of operation

BrianG · 03.16.2009, 02:33 AM

Hmm, anyone remember Schulze?

e-mike · 03.16.2009, 06:08 AM

Quote:

Originally Posted by eovnu87435ds

So I was running my converted hyper 7 PBS today when every Brushless R/C driver's nightmare came true for me... my Mamba Monster died

My setup was as follows.
10/46 gearing
MMMv3 (already replaced once)
Spektrum Sr3100 Rx
Spektrum DX3.0
Castle Neu 2650kv Monster combo motor
Airtronics servo
2 RC-Monster 2s2p 28/50c 5200mAh lipos in series (4s total)

MMM settings were all lightest for bashing purposes, and my cutoff was manual at 12.3v

In the beginning of the day, I was running it around the yard, tearing up the lawn, etc... and it ran fine for a half hour until i had to go... I came back later the same day, and continued to run the same setup, batteries were about half dead when i started.

Things were fine for about 5 minutes, when it stopped responding. It seemed to go to safety signal, as if it lost connection with the Tx. I restarted the Tx, and it reconnected and ran again. I did a run down the street at about 3/4 throttle, when it stopped again. Thats when I noticed my body glowing, and smoke billowing out of it. And I mean billowing- you couldn't see past the cloud of smoke it was so thick.

By the time i reach my hyper(~200 ft away)the smoke and fire had stopped. I ripped the body off and saw nothing but horror. I went to disconnect the batteries, and thats when I saw that my RC-M lipos were puffed.

Upon further inspection, one of the 6.5mm bullets was de-soldered from the MMM, as well as the negative battery input wire. they were both extremely hot.

After looking at the carnage and discussing it with ben(brushlessboy16) I think I have an idea of what happened... It seemed that the MMM overheated to the point where the one bullet became desoldered. Since there were only 2 phases operating the rotor would bounce between the 2 phases. Since the rotor wasn't spinning, the MMM was pulling more and more current to try and make the rotor spin, causing it to overheat eve more and catch fire and smoke. The extra amperage being pulled was then too much for the batteries. It would've finally stopped when enough current was being pulled from the batteries that the negative wire desoldered from the MMM as well.

Some other bits of info that might help in diagnosing this problem is that the drivetrain was completely free, so there was nothing mechanically holding anything back (if there even is anything that could), and the negative bullet was melted into the female bullet of the battery. What I still dont understand is why it would intermittently stop, and then work when i restarted my Tx, and what originally caused the MMM to heat up to the point where the bullet was desoldered...

Any help or support would be greatly appreciated

same thing hapenned to me this weekend....

Arct1k · 03.16.2009, 06:18 AM

Well amazed by your setup - 30 mins on a set of 5k batteries and only half done.

My guess is that the ESC stopped for LVC or such - when you rearmed it counted a 3s - When you ran again batteries could cope, this resulted in ripple hell and esc explodes into a dead short and getting crispy... New lipos required...

brushlessboy16 · 03.16.2009, 06:49 AM

If he has a custom lipo cutoff, it cant rearm into 3s mode.

eovnu87435ds · 03.16.2009, 07:54 AM

Quote:

Well amazed by your setup - 30 mins on a set of 5k batteries and only half done.

My guess is that the ESC stopped for LVC or such - when you rearmed it counted a 3s - When you ran again batteries could cope, this resulted in ripple hell and esc explodes into a dead short and getting crispy... New lipos required...

When you use really light settings on your MMM it gives you more runtime because it is not pulling as many amps. As for the lvc, I do have it at a manual cutoff... I dont trust many automatic things when it comes to R/C just for that reason.

[QUOTE] How many flux esc's have failed ??? And I've only heard of about 4-5 MMMV3s failing (just on here).... And recognizing the amount of MMMV3s already being sold (due to on sale/sold out listings both online/eBay/LHS I still think the MMMv3s still have a pretty high sucess rate....EVERYOnE will post their MMMV3 problems and that's understandable....however , how many people actually post their success with the MMMv3s.....sucks that your MMMV3 has smoked though....BTW my MMMv1 finally died a silent death yesterday after almost 10 months of operation Today 01:42 AM [QUOTE]

I'm not sure about just 4 or 5 MMMv3. I've had 2 die on me(this being the 2nd) and theres about 5 more that just died within 12 hours of mine. I'm not worried about the MMM, because I know castle puts its customers first... I just don't know what to do about loosing $200 worth of batteries

Arct1k · 03.16.2009, 08:06 AM

Does the Hyper run odd ratios else you are way undergeared...
Differential Ratio: 3.3076923076923075
Transmission Ratio: 1
Other Ratio: 1
Spur Tooth Count: 46
Pinion Tooth Count: 10
Total Voltage: 14.8
Motor KV: 2650
Tire Diameter (inches): 4
Tire Ballooning (inches): 0
Motor Current Draw: 0
Motor coil Ω: 0
Spur/Pinion Ratio: 4.6 : 1
Total Ratio: 15.21538 : 1
Tire Circumference (inches): 12.57 inches (319.19 mm)
Total Motor Speed: 39220 RPM
Vehicle Speed: 30.67 mph (49.27 km/h)
Effective KV Value: 2650
KT constant: 0.51 oz-in/A

Arct1k · 03.16.2009, 08:11 AM

Also apparent from your own thread that this ESC has had some abuse

Quote:

Originally Posted by eovnu87435ds

at least whoever did learned a valuable lesson about lipos... on another note, i have videos! At the end of the last video you dont see the hyper again til it falls out of the sky... It landed on all fours(like a puma), but it still hit the ground kinda hard... all that happened is that it unvelcro-ed the mmm and rx, and desoldered a wire off my deans. i was back up and running in 5 minutes!

If your solder joints are coming undone from a landing could mean you had a problem with other joints and had a lot of resistance in the system...

Lightening can strike twice or it could be setup related...

brushlessboy16 · 03.16.2009, 10:17 AM

Quote:

Originally Posted by Arct1k

Also apparent from your own thread that this ESC has had some abuse

If your solder joints are coming undone from a landing could mean you had a problem with other joints and had a lot of resistance in the system...

Lightening can strike twice or it could be setup related...

When you were jumping the hyper 7, was the wire desoldered or ripped off a cold joint?

Think he was running 12/46 but im not sure.

lutach · 03.16.2009, 11:12 AM

I don't know if anyone noticed the black shorted spot on the connector. Well, that's the part of my connector that is touching the heat sink. Patrick will see this, but I'm still thinking the connector touching the heat sink might be causing some problems. I still haven't used my MMM due to all the connectors touching the heat sink.

eovnu87435ds · 03.16.2009, 03:43 PM

When jumping a wire was ripped off the cold joint of the battery splitter. Definitely some sort of cold solder joint or shearing force, All temps were fine and there were no signs of overheating when i was jumping...

I was running 12/46 while jumping, but that pinion flew off and was lost so i was running 10/46 when it blew... And always before my runs I check for anything loose screws, wires, etc... Nothing else seemed like a bad solder joint, especially with the way the splitter was soldered, I dont think they would've held together under a cold joint

eovnu87435ds · 09:38 PM

I just got off the phone with castle, and, as expected with their excellent customer satisfaction rating, they are replacing my MMM... If only they could do something for my lipos too...